Abstract
Organoids are in vitro models that originated from the three-dimensional culture of stem cells with the ability to reproduce part of the in vivo structural and functional specificities of body organs. Intestinal organoids have great relevance in cell therapy, as they provide more accurate information about tissue composition and architecture in relation to two-dimensional culture, in addition to serving as a study model for host interaction and drug testing. The yolk sac (YS) is a promising source of mesenchymal stem cells (MSCs), which are multipotent stem cells with self-renewal ability and potential to differentiated into mesenchymal lineages. Besides this, the YS is responsible for the formation of intestinal epithelium during embryonic development. Thus, the aim of this study was to verify if the three-dimensional in vitro culture of stem cells derived from the canine YS is capable of developing intestinal organoids. MSCs from the canine YS and gut cells were isolated and characterized, then three-dimensionally cultured in Matrigel. In both cells lineages, spherical organoids were observed and after 10 days the gut cells formed crypt-like buds and villus-like structures. Despite having the same induction of differentiation process and having the expression of intestinal markers, the MSC from the YS morphology was not in the form of crypt budding. The hypothesis is that these cells could generate structures equivalent to the intestinal organoids of the colon that other studies showed formed only spherical structures. The culture of MSC from the YS, as well as the establishment of protocols for 3D cultivation of this tissue, is relevant, as it will serve as a tool in various applications in basic and scientific biology.